I got my Impact in is very cold January winter and places I was able to travel to to hunt had me wearing a long-sleeved flannel shirt and a warm coat. At times the clothing was almost too think for the Impact's cuff. In spring, and now in our chilly-to-cool fall, I find it very comfortable. During the blazing hot summer we had, with temps to 113°, I wasn't wearing anything close to being long-sleeved and yes, the Impact's arm cuff might be considered, by some, to have a little too much 'wiggle room.'
For me, it is fine. It allows ample room for wearing a sweater, jacket or thick warm coat, and when it's just the Impact Vs my bare arm, I just snug the arm cuff strap a little more. I never since any of my arm cuff traps down tight with any detector since I like to slip my arm out during a recovery and just slide it back in. So, for me, I don't find the cuff size and shape to really be too annoying, but then that's also because I use a slow-motion and methodical sweep. For those who sweep too briskly or maybe extend the rod out too far, that can create more of a 'loose-fit' feeling.